Improvement in phonograph or speaking machines



` l 4UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.

IMPROVEMENT IN PHONOGRAPH OR SPEAKING MACHINES.

Specification forming part of Letters Patent No. 200,521, dated February 19, 1878; application filed December 24, 1877.

To 'all whom it may concern:

Beit known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented an ImprovementJ in Phonograph or Speaking Maic hines, of which the following is a specificaion:

The object of this invention is to record in permanent characters the human voice and other sounds, from which characters such sounds may be reproduced and rendered audible again at a future time.

Thev invention consists in arranging aplate, diaphragm, or other flexible body capable of being vibrated by the human voice or other sounds, in conjunction with a material capable of registering the movements of such vibrating body by embossing or indenting or altering such material in such a manner that such register-marks will be sufficient to cause a second vibrating plate or body to be set in motion by them, and thusreproduce the motions of the first vibrating body.

The invention further consists in the various combinations of mechanism to carry out my invention.

I have discovered, after a long. series of experiments that a diaphragm or other body capable of being set in motion by the human voice does not give, except in rare instances, superimposed vibrations, as has heretofore been Supposed, but that each vibration is separate and distinct, and therefore it becomes possible to record and reproduce the sounds of the human voice.

In the drawings, Figure 1 is a vertical section, illustrating my invention, and Fig. 2 is a plan of the same.

' A is a cylinder having a helical indentinggroove cut from end to end-say, ten grooves to the inch. Upon this is placed the material to be indented, preferably metallic foil. This drum or cylinder is secured to a shaft, X, having at one end a thread cut with ten threads to the inch, the bearing P also having a thread cut in it.

L is a tube, provided.with a longitudinal slot, and it is rotated by the clock-work at M, or other source of power.

The shaft X passes into the tube Il, and it is rotated by a pin, 2, secured to the shaft,

and passing through .the slot on the tube L, the object of the long slot being to allow the shaft X to pass endwise through the center or support P by the action of the screw on X. At the same time that the cylinder is rotatedl it passes toward the support O.

B is the speaking-tube or mouth-piece, which may be of any desired character, so long as proper slots or holes are provided to re-enforce the hissing consonants. Devices to effect this' object are shown in my application, No. 143, filed August 28, 1877. Hence they are not shown or further described herein.

Upon the end of the tube or mouth-piece is v a diaphragm, having an indenting point of hard material secured to its center, and so arranged in relation to the cylinder A that the point will be exactly opposite 'the groove in the cylinder at any position the cylinder may occupy in its forward rotary movement.

The speaking-tube is arranged upon a standard, which, in practice, I provide with devices for causing the tube to approach and recede from the cylinder.

The operation of recording is as follows:

The cylinder is, by the action of the screwin X, placed adjacent to the pillar P, which' brings the indenting-point of the diaphragm G opposite the first groove on the cylinder, over l which is placed a sheet of thick metallic foil, f

paper, or other yielding material. The tube B is then adjusted toward the cylinder until the indenting-point touches the material and indents itslightly. The clock-work is then set running, and words spoken in the tube Bwill cause the diaphragm to take up every vibration, and these movements will be recorded4 with surprising accuracy by indentations 1n the foil.

After the foil on the cylinder has received the required indentations, or passed to its full limit toward O, it is made to' return to P by proper means, and the indented material is brought to a position for reproducing andrendenin g audible the sounds that had been made by the person speaking into the tube B.

C is a tube similar to B, exceptthat the diaphragm is somewhat lighter andi moresensi tive, although this isnot actually necessary. In front of this diaphragm is a light spring,

D, having a small point shorter and finer thaL.-L J

' cate the indenting-point on the diaphragm of I). This spring and point are so arranged as to .all exactly into the path of all the indentations. This spring is connected to the diaphragm F of C by a thread or other substance capable of conveying the movements of D. Now, when the cylinder is allowed to rotate, the spring D is set in motion by each indentation corresponding to its depth and length'. This motion is conveyed to the diaphragm either by vibrations through a thread or directly by connecting the spring to the diaphragm F, and these motions being due to the indentations, which are an exact record of every movement of the rst diaphragm, the voice of the speaker is reproduced exactly and clearly, and with suiicient volume to be heard at some distance.

. The indented materialmaybe detached from the machine and preserved for any length of time, and by replacing the foil in a proper manner the original speakers voice can be reproduced, and the same may be repeated frequently, as the foil is not changed in shape if the apparatus is properly adjusted.

The record, if it be upon tin-foil, may be stereotyped by means of the plaster-of-paris process, and from the stereotype multiple copies may bemade expeditiously and cheaply by casting or by pressing tin-foil or other material upon it. This is valuable when musical compositions are required for numerous machines.

It is obvious that many forms of mechanism maybe used to give motion to the material to be indented. For instance, a revolving plate may have a volute spiral out both on its upper and lower surfaces, on the top of which the foil or indenting material is laid and secured in a proper manner. A two-part arm is used with this disk, the portion beneath the disk having a point in the lower groove, and the portion abovethe disk carrying the speaking and receiving diaphragmic devices, which arm is caused, by the volute spiral groove upon the lower surface, to swing gradually from near the center to the outer circumference of the plate as it is revolved, or vice versa.

An apparatus of x this general character 4adapted to a magnet that indents the paper is shown in my application for a patent, N o.-

128, filed March 26, 1877; hence no claim is made herein to such apparatus, and further description of the same is unnecessary.

' A Wide continuous roll of material may be used the diaphragmic devices being reciprod by proper mechanical devices backward and forward over the roll as it passes forward; ora narrow strip like that in a Morse register may be moved in contact with the indentingpoint, and from this the sounds may be reproduced. The material employed for this purpose maybe soft paper saturated or coated l with paraine or similar material, with a sheet of metal foil on the surface thereof to receive the impression from the indenting-point.

v do not wish to confine myself tov reproducing sound by indentations only, as the transmitting or recording device may be in a sinuous form, resulting from the use of a thread passing with paper beneath the pressure-rollers t, (see Fig. 3,) such thread being moved laterally by a fork or eye adjacent .to the roller t, and receiving its motion from-the diaphragm G, with which such fork or eye is connected, and thus record the movement of the diaphragm by the impression of the thread ill the paper to the right and left of a straight line, from which indentation the receivingdiaphragm may receive its motion and the sound be reproduced, substantially in the manner I have already shown; or the diaphragm may, by its motion, give more or less pressure to an inking-pen, u, Fig. 4, the point of which rests upon paper or other material moved along regularly beneath the point of the pen, thus causing more or less ink to be deposited upon the material, according to the greater or lesser movement of the diaphragm. These ink-marks serve to give motion to a second diaphragm when the paper containing such marks is drawn along beneaththe end of a lever resting upon them and connected to such diaphragm, the lever and diaphragm being moved by the friction between the point being greatest, or the thickness of the ink being greater where there is a large quantity of ink than where there is a small quantity. Thus -the original sound-vibrations are reproduced upon the second diaphragm.

' I claim as my invention- 1. The method herein specified of reproduci ing the human voice or other sounds by causing the sound-vibrations to be recorded, substantially as specified, and obtaining motion from that record, substantially as set forth, for the reproduction of the sound-vibrations.

2. The combination, with a diaphragm exposed to sound-vibrations, of a moving surface of yielding 'material-such as metallic foilupon which. marks are made corresponding to the sound vibrations, and of a character adapted to use in the reproduction ofthe sound, substantially as set forth.

3. The combination, with a surface having marks thereon corresponding to sound-vibrations, of a point receiving motion from such marks, and a diaphragm connected to said point, and responding to the motion of the point, substantially as set forth.

4. In an instrument for'making a record of sound-vibrations, the combination, with the diaphragm and point, of a cylinder having a helical groove and means for revolving the cylinder and communicating an end movement corresponding to the inclination of the helical groove, substantially as set forth.

Signed by me this 15th day of December, A. D. 1877.

THOS. A. EDISON.

Witnesses: V

GEo. T. PINCKNEY, I CHAS. H. Smm. 

